Nebraskaland

APRIL 2017 • NEBRASKAland 69 Y ou will hear a lot of talk among anglers about spawning activities of a variety of fish this time of year. Some of that talk will be right, but there are a lot of misconceptions, too. Let me see if I can cast some light on the spawning activities of some of our Nebraska fish. First of all, understand that fish invest a lot of energy into the production of "gametes"– a term that means sex products, eggs and milt in fish. The development of eggs and milt in our Nebraska fish takes weeks, months even. As a matter of fact, many of our species begin developing gametes in late summer through fall of the year before. Some folks clean a fish they caught in the fall, see eggs and assume those fish are going to spawn in the fall. But they do not. Those are eggs developing for the spawn the following spring, when they will rapidly mature and be deposited depending on the species of fish. Rainbow trout are a coldwater species, and most rainbows are winter/ late winter/early spring spawners. We do not depend on natural reproduction of rainbow trout in any Nebraska fisheries, but you may see some rainbows in spawning colors and exhibiting some spawning behavior in the winter and early spring. Northern pike spawn right after ice- out and in years when we may have a late ice-out, spawning will start under the ice. Walleye and sauger then spawn, followed by yellow perch and then muskies. Next, white bass spawn and are followed shortly by crappies, smallmouth bass, largemouth bass and then common carp. Sunfish species spawn next, including bluegill, rock bass, green sunfish and redear sunfish. Our catfish species spawn each summer, with blues, channels and then flatheads occupying their spawning territories into July. Lastly, in the fall Nebraska has two spawning fish species – brown and brook trout. Regarding what triggers spawning, there can be several variables that influence the timing of spawning. Those "cues" even can vary from one habitat to another even for the same species of fish. For example, fish living in moving waters, such as large rivers, can be triggered to spawn by rising water in the spring, while the spawning of the same species of fish living in standing water, a reservoir, may not be influenced by water levels at all. Water temperature and weather patterns can also influence the timing of spawning, but those "magic" temperatures that are often quoted, for example "largemouth bass spawn when the water is 62 degrees F," are inaccurate. If absolute water temperatures were the cue to spawning, there would be a lot of spawns ruined by spring warming trends followed by strong cold fronts and dropping temperatures. Photoperiod or the amount of daylight is another cue that triggers reproductive behavior in Nebraska's fish. Therefore, spawning will tend to occur at about the same time every year. I have seen walleye spawning April 1 the day after the ice went out, and I have seen walleyes spawning April 1 when we have had very warm weather for most of the month of March. Yes, weather patterns may influence spawning activity but it only "modifies" that activity, making it vary a bit from year to year but not changing spawning times by weeks. Also keep in mind that Nebraska is a large state with a great deal of variability in habitat, weather and climate. For example, you may see largemouth bass spawning behavior as early as late April in southeastern ponds, while that same species will still be spawning into June in northern and western parts of the state. Also, not all fish spawn at the same time; in any population there will be individual fish that tend to spawn early and there will be individual fish that tend to spawn late. If all the fish in a population spawned at the same time, one ill-timed cold snap could eliminate an entire year's reproduction. And what does all this do for catching fish? During the spawn fish will concentrate and feeding activity may occur right up until the fish are ready to spawn. But, once spawning begins, fishing actually slows. In fact, if you fish for a variety of species, and fish different waters, you can "ride waves" of good pre-spawn and post- spawn fishing for several different species of fish. Having said all of this, it is important to protect big fish because those fish are likely some of the best broodstock in a population. The fact that an individual fish reached exceptional size suggests that fish has been one of the most successful at surviving, is one of the fastest-growing, and likely has traits, genetics, that would be desirable in a population. If at all possible, turn the big ones loose, regardless of species and regardless of when they are caught. ■ Daryl Bauer is a fisheries biologist with the Commission, as well as fish and wildlife program manager. He holds over 70 Nebraska Master Angler Awards for 13 different species. Read his Barbs and Backlashes blog at Outdoornebraska.org to learn even more about fishing. Spawn is in the Air Every Nebraska fish species spawns a little different. By Daryl Bauer Pictured is a redear sunfish close to spawning. PHOTO BY DARYL BAUER

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